The invention relates to an edge support system for a mattress.
Innerspring mattresses are typically assembled by aligning a matrix of coils and tying the coils together at each terminus with helical wires. The coils located at the border of the matrix and the helical wires are secured to border wires that frame the coil matrix in the plane of each coil terminus. Similar innerspring assemblies may be used in the construction of furniture other than mattresses such as upholstered chairs and sofas. The innerspring assembly of coils and wires is wrapped with layers of padding, bunting, ticking and upholstery materials to provide a comfortable surface upon which a person may sit, lie, or sleep. Mattresses are typically assembled manually therefore it is desired that the mattress components be simple and fit together quickly and easily.
The edges or perimeter of the mattress generally require greater structural support to maintain the shape of the mattress. The greater edge support is required due to the need of mattress users to get on and off of the mattress from the perimeter. In so entering and exiting the mattress, a person may sit or stand on the edge of the mattress for a period of time. A person may also use the edge of a mattress as a seat. The coils of the innerspring located on the perimeter of the matrix will be subjected to increased loads and loading cycles by the sitting or standing of a person on the edge of the mattress. A person""s weight distributed among a few coils, as when the person is sitting, applies a more concentrated load on the affected coils than does a more even distribution on a coil array as when a person is lying on the mattress. The added loading and load cycles at the edges of the mattress accelerate the wear on the edges and results in a rounding off of the mattress edges. This rounding off is accentuated by the layers of padding and upholstery materials that converge at the edges of the mattress.
To provide extra support at the perimeter of a mattress the prior art mattresses have incorporated a wood border member or padding or foam inserts that interlockingly engage with the coils of the mattress innerspring. The wood border members result in a mattress that is heavy and therefore more difficult to move. Other edge supports consisting of padding or foam strip inserts have been inserted between every convolution of the coils or between and around individual helical coils. The foam strips or pieces generally include a planar wall on one side and the opposing wall is shaped to fit between adjacent coils or between the convolutions of the coils and are usually constrained between the upper and lower border wires. The inserts have required the use of special corner reinforcement pieces that fit around the coil located in the corner of an approximately rectangular array of coils in the innerspring.
The innerspring edge and corner support components are extruded and are often of complex cross-sectional area. The complex cross-sectional area requires additional extruder maintenance during manufacture thereby increasing costs and manufacturing time. Additional extruded foam pieces of the mattress assembly also complicate the tailoring of the mattress by adding layers of material that must be sown around or incorporated into the stitches of the tailoring. The number of individual edge and corner support components required to add support around the entire mattress generally increase assembly time and costs.
Therefore, there exists a need for a mattress edge support system that may be continuously extruded and used for completely encompassing a mattress edge for added edge support. The mattress edge support system may be installed on the coil matrix of a mattress as one continuous strip or may be sectioned into smaller lengths where one or more smaller lenghts are installed on the coil matrix. There is further a need for a mattress edge support system that allows decreased assembly time and streamlines tailoring of the mattress.
The present invention provides a continuously extruded edge support insert for a mattress. The edge support has a C-shaped cross-section or the cross-section may gradually thicken from interior corners of the xe2x80x9cCxe2x80x9d toward the center forming a putative E-shaped cross-section. When installed on the mattress, the thickening of the cross-section may coincide with the convolutions of the innerspring, but does not require interlacing between the convolutions. The edge support is installed on the innerspring assembly so that it encompasses both of the border wires. The edge support component is economical to manufacture because it is a single extruded unit of simple cross-section and therefore will not demand excessive extruder maintenance. Mattress assembly is streamlined by the use of the single edge support unit because the edge is easily and quickly wrapped around the border wires of the entire innerspring assembly and eliminates the requirement of specially designed corner pieces for edge support. Alternatively, the edge support system may be cut into small lengths or sections after extrusion, or extruded in smaller lengths, and installed by sections during assembly of the mattress. Further, mattress tailoring is streamlined by the elimination of the additional foam or materials that would otherwise be present with the use of separate corner support pieces.